Coating with metal.



' which the molten zinc is ordinarily held. The alloy so i'orined is commonly known so 'Mzidison; count I of Dane State of Wisconspect to the iron or steel, end in many re- UNITED iisirnu'r OFFICE. I

CHARLES E BUIRGESQ, 0E MADISON, Wl 'i'SCQNFIN, AhSIGNOR TO UNITED STATES 'SHERABDIZING GOMPANY, 0F blEi/V CASTLE, PENNSYLVANIA, A GORPORATIQN OF NEW JETd-SEY.

1,014.,7d9. licllrawiug.

To all whom it may concern Be it known that l, (Jr-muons ll. Become, a. citizen of the United States, residing at sin,'l1uve invented certain new and useful Improvements in (looting with Motel, of which the following is a specitic'etion.

- The present invention relates to the art of covering metal or metallic objects with u protective or ornamental costing by melting use of 9. brittle alloy in egrenulsr condition wherein the article or object to be coated maybe heated. to receive its covering.

More particularly, it relates to the ertl of costing iron or steel with, a homogeneous end uniform covering, electro-positive with re-' spects diilerent from the zinc costing commonly used... I

My invention also embrece's the product thereby produced.

It is common practice in the art of costing metals to dip on iron object or article, after suitable cleaning, into a both of fused zinc, thereby producing on the surface of the iron cowering capable of, reiterating it from corrosion. This process as some disndvan toges or limitations, such, for exomple, us the deli er that the high tenipereture i'uey injure the iron or steel article during the coating operation, as by drawing the temper, and the difliculty of controlling the thickness and crystalline structure of the coating produced. Furthermore, the proc ass is expensive, not only because of the initial cost of the installation end of the fused bath of pure zinc, but also because of deterioration of the zinc bath. l" has been found that the molten zinc alloys with iron or steel objects dipped therein, and also alloys with the iron tank or receptacle in dross, and sinks to the bottom of the tank, from whence it must be removed from time to tim. This alloy enelyzes shoot 97% zinc, and 3% iron, and is sold at o comparatively low price as a. byproduct of the bot gslvon-l icing process.

iiccording to the present invention, the motel to be coated, say on iron or steel artiole, is suitably cleaned, by" send blasting endpickling", or the like, endthen is brought into contact with a zinc alloy, end hosted until it tubes on a protective coating or covspecificutiou of Letters Patent.

Application filed April 2, 1

CQATINQ WE'RE ihlTi-ilh.

Patented Jan. 16,1912.

w. Serial Ito. 553,940.

the alloy may be regirded as a saturated so-- In neking up this lution of iron in zinc. alloy, .itis not necessary to start with pure iron and pure zinc, but, on the contrary, it is possible to start with the zinc-iron allo or dross above referred to as the by-pro uct of hot galvanizing, adding sufficient iron to the fused alloy to bring the proportions up tosbout the. relation FeZn When madefrom' dross as a. basis, the FeZn alloy is relatively cheap- Aftercooling, this, zinc alloy, FeZn is very brittle, and can be crushed Without diiiiculty, and ground into a granularcondition. This brittleness is attributable to the presence of the Fezn -compound in such qusnity that its tendency to crumble or brook up will preponderate over the strengthening action of a residual uncombined zinc. With the alloy or compound FeZn the brittleness seems to be due to the extremely crystalline character of the materiel end to the pronounced development of cleavage planes and areas of mechanical weakness, this being so pronounced that the material produced as above described is so brittle that very often it may be crumbled into granular condition merely by pressure of the fingers. It need not be ground fine.

To cost it metal article, the zinc-iron alloy in granular form is applied to the surface of the article, and is there submitted to the action of heat until an adherent coating results. This operation may be efiected by placing the article in a closed. drum or re ceptacle, together with a quantity of the granular FeZn mid then heating to a. mod crate temperature. The air need not be totally excluded from the drum during this heating operation. The drum can be r0- tutcd to maintain intimate contact between the granular alloy and the iron article. and the temperature and duration of heating can be suitably regulated to govern the thickness of the coating. Heating fortwo hours and to a maximum temperature of about dull red, (700 to 800. deg. F.) gives good results. This temperature is well below the ular zinc-iron alloy of about the composition Width a protective layer, which consists in gill-restin the article at about dull red While with a protective layer 0 FeZn i ,TLThe processof coating an iron article m contact with FeZn 8. Theprocess of coating a metal article zinc-iron alloy which consists in heating the article to about dull red, while in contact with a zinc-iron reducing said alloyto granular condition, applying said granular- 1 materiaLtoan' iron surface, and submitting the-same to the action of heat to produce a u-u'nifo'rm adherent coating.

'10. The process of coating an iron article with a protective covering containing zinc,

';which consists in'adding iron to zinc-dross to form an alloy which ,is brittle, applying said brittle alloy in subdivided condition to the article tobe coated, and submitting the same to heat-..

11.- The process of coating an article with I a protective covering containing zinc and iron, which consists in adding metal to zincdross to form a material which is brittle, applying said brittle material in subdivided condition to'the article to be coated, and submitting the slime to heat. a

12. The product produced as herein described and coinprisiii an iron article having an electropositive coating which throughout is of about the composition FeZn said coating having a soft, silver color to the naked" eye, and a single-potential of about 0.23 volts. 13. Asa new product, a metallic object produced as herein described, and having a surface coating of zinc-iron alloy of about the compesition FeZn this coatin being characterized by a silver color, reedoin from crystalline structure when examined by the naked eye. a single potential lower than that of pure zinc, and a hardness somewhat greater than that ofpure zinc.

14. As a new roduct an. iron article coated as herein escribed with a homogeneous adherent covering consisting mainly of zinc, said covering having at its exposed surface a single potential less than that of zinc and havin a freedom from crystalline structure when examined by the naked eye. 9

v 15. The-process of coating a metal article which consists in applying thereto brittle alloy in granulancondition, saidalloy containing zinc and iron, and submitting the same to the action of heat. I

. 16. The process'of coating a metal which forms with zinc a brittle alloy reducible to ranular condition, said process consisting 1n applying to said metal said granular alloy, and submitting the same to the action of heat until the metal takes on a covering of said alloy,

CHARLES F. BURGESS. WVitnesses:

VROMAN MAMN, IRMA WISWALL.

In witness whereof, Ihave hereunto set my hand this 29th day of March. A. D. 1910. 

